3-1,4-Glucan 3-Glucanase

IV. PARASITISM. Lysis by hydrolytic enzymes excreted by microorganisms is a well-known feature of mycoparasitism. Chitinase and P-l,3 glucanase (laminarase) are particularly important enzymes secreted by fungal mycoparasites capable of degrading the fungal cell wall components, chitin, and P-1,3 glucan (131-134). 

Table L Synergism between Glucanases in C wriffis lysis (SCL) and Solubilization of Cell Wall Glucans (SCS)...

Table IV. Effect of Sequential Addition of Glucanases on the Lysis and Solubilization of C utilis Cell Wall Glucan...

Also referred to as endo-l,4-j8-glucanase and carboxy-methyl cellulase, this enzyme [EC 3.2.1.4] catalyzes the endohydrolysis of l,4-j8-D-glucosidic linkages in cellulose. The enzyme also catalyzes the hydrolysis of 1,4-Unkages in /3-D-glucans also containing 1,3-Unkages. 

This enzyme [EC 3.2.1.71], also known as endo-l,2-/3-glucanase, catalyzes the random hydrolysis of 1,2-glucos-idic linkages in l,2-)3-D-glucans. 

Varghese and coworkers have identified the active site nucleophiles of two crystalline ) -D-glucan endohydrolases from germinating barley [70]. In more recent work, Hej and coworkers were able to introduce 2,3-epoxypropyl- -laminaribioside 8 (n = 1) into the active site of the crystalline l,3-/3-D-glucanase from barley [71]. A subsequent X-ray crystallographic investigation gave invaluable information about the active site of this enzyme and the point of attachment between enzyme and inhibitor was confirmed. 

Glucanase -Glucans of barley oats Reductions of sticky droppings Improved feed utilization... 

These polymers are distinguished from cellulose by the presence of both/ -(l— 3)- and / -(l— 4)-linked D-glucosyl residues, lower molecular weights (some noncellulosic glucans are water-soluble), and susceptibility to hydrolysis by / -D-glucanases that cannot hydrolyze cellulose. Unlike cellulose, whose microfibrillar structure and structural role in the cell wall has been clearly established, the function of these polymers as structural components of the wall is still a subject of controversy there is some evidence that they are energy-reserve materials.110-201 202... 

Hydrolysis by endo-( 1 -> 3)-a-D-glucanase has demonstrated the presence of consecutive a-(l - 3) linkages in a number of streptococcal a-D-glucans (mutans). Insoluble a-D-glucans produced by S. mutans OMZ 176 and OMZ65 were hydrolyzed by endo-(l- 3)-a-D-glucanase, whereas the soluble polysaccharides from the same sources, and dextran T-2000, were... 

---